Spray gun for applying plaster and the like



May 19, 1959 s. v. SWENSON 7 2,837,274

, SPRAY GUN FOR APPLYING PLASTER AND THE LIKE Filed Feb. 20. 1958 28 2e42 g\49 c Inuen'tbr 5 an. V- Swanson.

United States Patent SPRAY GUN FOR APPLYING I'LASTER AND THE LIKE SwanV. Swanson, Minneapolis, Minn. Application February 20, 1958, Serial No.716,315

Claims. (Cl. 239-371) My invention relates to improvements in. sprayguns, particularly such guns of the type adapted to apply plaster andthe like.

In a spray gun for plaster and similar materials, it is desirable thatthe gun be conveniently manipulated and variably regulated by one handof the user leaving the other hand normally free.

It is further desirable that a spray gun of the nature indicated becapable of being so adjusted in regulation of its output that anyselected adjustment made may be maintained, as desired, withoutexpenditure of effort on the part of the user.

Additionally it is importantly desirable that a spray gun of the presentnature. be not onlysimple, durable and inexpensive in construction. andefficient in operation, but that it be adapted to be quickly and easilydismantled to an extent rendering the parts thereof capable of beingreadily washed clean of the plaster or other material accumulatingthereon in use, and that the parts may be quickly and easily reassembledfor subsequent use. of the gun.

It is an object of my invention to provide a spray gun constructed inattainment of the various: desiderata aforesaid.

J Other objects of the invention reside in the novel combination andarrangement of parts and in the details of construction hereinafterillustrated and/or described.

In the drawing:

Fig. l is a side elevational view of a spray gun constructed inaccordance with my invention, portions of. the: structure being brokenaway to reveal otherwise concealed construction.

Fig. 2 is a fragmentary front elevational view of said spray gun.

t Fig. 3 is a fragmentary rear elevational view of said spray gun.

Fig. 4 is a transverse sectional view taken as on the line4-4 of Fig. 1,portions of the structure being broken away to disclose internalconstruction of some of the parts. a

Reference being had to the illustrated form of my invention, it will beseen that it includes a body A having a'chamber it} therein and a handle11, like that of a pistol, depending from said body A. At the top of thebody A isan: annular flange 12 defining an opening leading into saidchamber 1t Fitted into said flange 12 is the lower reduced end 13 of ahopper 14' for the supply of. material to be sprayed, said hopper 14being provided at the top thereof with a material-retaining flange 15 toprevent the spillage of material from the hopper when the gun is tiltedrearwardly, as in spraying. anelevated area. At the front of the body Ais an. annular flange 16 defining an opening communicating with thechamber 10 in said body. A nozzle 17 removably fitted into the front.annular flange 16 has a peripheral flange 18 overreaching the forwardface of said front flange of the body A. This nozzle flange 18 is.formed with diametrically opposed outwardly opening slots 19 receiving'ice threaded studs 20 screwed into said body flange 16 and fitted withwing nuts 21 adapted to be turned against said nozzle flange 18 to clampsaid nozzle 17 in place within said front flange 16 of the body A. Thenozzle 17 is formed with a discharge orifice 22 having at the rearthereof an annular valve seat 23. The gun is furnished with a number ofnozzles, the discharge orifices of which vary in diameter to suitvarious conditions arising in usage of the device. At the rear portionof the body A is a boss 24 which extends forwardly into the chamber 10of the body A and rearwardly to the rear of said body. This boss 24 hasa bore 24 therein occupied by a bushing 25, which receives a main stem26 of a cylindrical valve member B, said stem26 of said valve member Bbeing longitudinally slidable and rockable in said bushing 25. The bore24 in the boss 24 is enlarged and interiorly threaded at its rearportion, as at 24", to receive a packing nut 27 through which said mainstem 26 of the valve member B extends.

The forward portion of the stem 26 of the valve membet E is conicallyformed, as at 28, for coaction with the valve seat 23 of the nozzle 17.Thus formed, the valve stem 26, in the foremost position of itslongitudinal sliding movement, will engage said valve seat 23 and closethe orifice 22 in the nozzle 17 against discharge therefrom of materialintroduced into the chamber 10 of the body A from the hopper 1d. Saidstem 26 of said.v

valve member B is formed with an axial bore 29 into: which air underpressure is introduced, as will more fully hereinafter appear. Inretracted longitudinally adjusted positions of the stem 26 of the valvemember B, the discharge orifice 22 in the nozzle 17 is obstructed ingreater or lesser degree by said stem whereby the flow of material fromthe chamber 10 of the body A is regulated, such material being impelledfrom said chamber 10 through the discharge orifice 22 and sprayedtherefrom by the blast of air issuing from the bore 29 in said stem 26of the valve member B. Said valve member B includes a tail piece 30 inthe form of a length of pipe which is axially aligned with the valvestem 26 and coupled thereto by means of a nipple 31. At itsforwardportion, this nipple 31 receives the reduced exteriorly threaded rearportion 32 of said stem 26 of the valve member B, and at its rearwardportion, said nipple 31 receives the exteriorly threaded forward portion33 of said tail pipe 30 of the valve member B. When the gun is in use,said tail pipe 30 is coupled at its rearward end to an air supply hose,as at 3 leading from any suitable source of air under pressure.

The valve member B is spring loaded and normally yieldingly held withits stem 26 in orifice-closing contact with the valve seat 23 at theinner end of the orifice 22 in the nozzle 17. Said valve member B isthus loaded by a helical expansion spring 35 encircling the couplingnipple 31 and the forward portion of the tail pipe 30 of said valvemember. In reducing the end 32 of the valve stem 26 to accommodate saidnipple 31, a shoulder 36 is formed on said stem. A front abutment forthe spring 35 is constituted by a plate 37 which has an opening thereinreceiving said reduced end 32 of the valve stem. 26, said plate 37 beingrigidly clamped between said shoulder 36 and the forward end of thecoupling nipple.

, sion of upwardly opening notches 41 which individually receive thelower edge of the latch lever 40, upon ap-' Patented May 19, 1959propriate longitudinal adjustment of the valve member B, and releasablysecure the thus adjusted valve member B against the action of the spring35.

In using the spray gun, an operator can apply his free hand to the latchlever 40 and employ it as a means for retracting the valve member B intoany desired position of its longitudinal adjustment. Said latch lever40, however, has for its principal purpose the latching of said valvemember B in any selected position of adjustment into which said valvemember may be retracted by means of a trigger D which is associated withthe pistol-like handle 11. This trigger D includes a rod 42 slidablymounted in a way 43 formed at the junction of the body A and handle 11,said rod 42 being slidable relative to the body A in parallelism withthe valve member B. Said trigger rod 42 has a finger piece 44 dependingfrom its forward end in position to be engaged by the index finger of ausers hand grasping the handle 11.

The plate 37, which, as aforesaid, provides an abutment on the valvemember B for the forward end of the spring 35 and which has said latchlever 40 thereon, constitutes also a coupling medium between the triggerrod 42 and valve member B. A depending portion 37 of the plate 37 has anarcuate slot 45 therein formed with an enlargement 46 at the end thereofnearest to the arm 39 of the bracket C. Said slot 45 follows an arcstruck from the axis of the valve member B, the radius of said are beingequal in length to the distance between the axes of said valve member Band trigger rod 42. Thus, said slot 45 is intersected by the axis ofsaid trigger rod 42, the enlargement 46 of said slot 45 being adapted totake position in axial coincidence with said trigger rod axis in oneposition of said coupler plate 37 in which it may be stationed. Thetrigger rod 42 is detachably connected to the coupler plate 37 throughthe medium of said slot 45, the rearward end of said rod 42 being formedwith an annular groove therein providing a reduced reach 47 axially ofthe rod 42 and relatively spaced shoulders 48 and 49, the former beinglocated forwardly of the reach 47 and the latter located rearwardlythereof. Said reduced reach 47 of the trigger rod 42 is normallyreceived within the slot 45 of the coupler plate 37 with the frontshoulder 48 on said rod'42 proximately facing the forward face of thecoupler plate 37 and the rear shoulder 49 on said rod proximately facingthe rearward face of said plate. Upon pulling the trigger D, rearwardmovement of the trigger rod 42 is imparted to the valve member Bretracting the same. Conversely, forward movement of the valve member B,by action of the spring 35, is imparted to said trigger rod 42,returning the trigger D, under control of the users trigger finger, tostarting position wherein the valve member B closes the dischargeorifice 22 in the nozzle 17. In connecting the coupler plate 37 to ordisconnecting it from the trigger rod 42, the former is swung,counterclockwise as seen in Fig. 3, into position bringing theenlargement 46 of the slot 45 into axial coincidence with the axis ofsaid trigger rod 42. With the coupler plate 37 and trigger rod 42 thusrelatively disposed, the said parts may be disconnected from each othersimply by shifting one thereof longitudinally relative to the other tocause the rear shoulder 49 on the trigger rod 42 to be withdrawn fromthe plate 37 through said enlargement 46 of the slot 45 in said plate.To connect the coupler plate 37 to the trigger rod 42, the reverse ofthe aforesaid operation is performed and thereafter followed byswingably returning the coupler plate 37 into position bringing thereduced reach 47 of the trigger rod 42 into the slot 45 in said plate37. t

Disconnection of the coupler plate 37 from the trigger rod 42 is one oftwo steps taken in freeing the valve member B for its withdrawal fromthe body A to enable said valve member B and the interior of the body Aand hopper 14 to be readily and thoroughly washed to clean therefrom allplaster or the like which has accumulated there- 4 on. Another stepwhich is taken to free the valve member B for its withdrawal from thebody A involves the pivoting of the forward end of the aforesaid arm 39of said bracket C to said body A so that said arm 39 may be swung downaway from said valve member B. Said forward end of said arm 39 liesagainst the outer face of a side extension 50 of the body A. A headedscrew 51 extending through said bracket arm 39 and threaded into saidextension 50 of the body A provides a pivotal bearing for said arm 39about which the bracket C is swingable. Normally, to retain theswingable bracket C in operative disposition wherein its flange 38provides a rear abutment medium for the spring 35, a washer 52 isemployed, the same having a retainer lip 53 turned outwardly therefrom.This washer 52 fits about the tail pipe 30 of the valve member B and isnormally interposed between the rear end of the spring 35 and theforward face of the abutment flange 38 of said bracket C, the retainerlip 53 in such case being in underlying engagement with the lower edgeof said flange 38 in opposition to the opening of an upwardly openingnotch 54 in said flange 38 in which notch 54 said tail pipe 30 isreceived, such engagement of said lip 53 with said flange 38 normallypreventing the downward swinging of the bracket C away from the valvemember B. To effect the downward swinging movement of the of the bracketC and thereby shift it out of the way of the valve B for the withdrawalof said member from the body A, the washer 52 is forced forwardly alongthe tail pipe 30 against the action of the spring 35 sufliciently tofree the washers retainer lip 53 from the abutment flange 38 of saidbracket C, whereupon said bracket will swing downwardly into positionclear of said valve member B. To return the bracket C into its operativerelationship with the valve member B, the reverse of said operationaforesaid is performed as will be readily understood.

When the bracket C is operatively disposed, the arm 39 thereof providesa stop limiting the downward throw of the latch lever 40 so that untilthe bracket C is downwardly swung away from the valve member B, thelatch lever 40 is prevented from swinging downwardly sufliciently tobring the slot enlargement 46 in the coupling plate 37 into positionwherein the rear shoulder 49 on the trigger rod 42 could beunintentionally withdrawn therethrough.

From the foregoing, it will be appreciated that I have provided aconstruction in spray guns which well meets the aforementionedobjectives of my inventiona con struction which, among other things,features the convenient manipulation of the gun in one hand and theregulation of the output of the gun by the same hand; the readyreleasable latching of the valve member in selected positions of itsadjustment; the selection and arrangement of parts in a simple, durableand effective organization making for ease and dispatch in the limiteddismantling thereof required for cleaning purposes, and making for thequick and easy replacement of parts preparatory to the resumption of useof the gun.

Changes in the specific form of the invention, as herein described, maybe made within the scope of what is claimed without departing from thespirit of the invention.

Having described the invention, What is claimed as new and desired to beprotected by Letters Patent is:

1. In a spray gun for applying plaster and the like, a body having achamber therein and a material-receiving opening leading thereinto, anozzle in the front portion of the body having a discharge orificeleading forwardly from said chamber, a cylindrical valve member mountedin the rear portion of the body in axial alignment with the axis of saidorifice, said valve member being axially movable for withdrawal from andfor longitudinal adjustment and rotational rocking movement relativetosaid body, said valve member coacting at its forward portion with saidnozzle to close said orifice and to open the same in varying degreeaccording to the longitudinal adjustment of said valve member, saidvalve member having therein an axial' passageway for the passage: of airtherethrough, said" valve member being adapted to be connected at itsrearward end with a flexible air line to supply said air passageway withair under pressure, a handle depending from the body, a trigger rodslidably mounted in the body in parallelism with the valve member, saidrod having a finger piece depending therefrom forwardly of the handle inposition accessible to the finger of a hand grasping said handle, acoupler plate fixed to the valve member transversely thereof rearwardlyof the handle, a releasable key slot connection between said trigger rodand coupler plate, said connection 1ncluding a slot in said couplerplate curvedalong an arc struck from the axis of the valve member, saidplate having a slot"enlarging"openingtherein at one end of said slotadapted to take position in axial coincidence with the axis of thetrigger rod, the rear portion of said trigger rod having a reduced reachaxially thereof and also having relatively spaced shoulders forwardlyand rearwardly ofsa'id reduced reach, said slot enlarging opening beingadapted to receive and accommodate the passage of said rearward shouldertherethrough, the slot being adapted to receive said reduced reach, andsaid shoulders being adapted to engage opposite faces of the couplerplate along said slot, a vertically swingable bracket having an armpivoted at its forward end to said body, said arm having at its rear endan inturned abutment flange formed with an upwardly opening notchadapted to receive the rear portion of the valve member, a washerslidable along said rear portion of the valve member, said washer beingnormally backed against said abutment flange and having at its lowerportion a rearwardly extending lip normally in underlying engagementwith the lower edge of said abutment flange, a helical expansion springencircling the valve member and interposed between said washer and saidcoupler plate, said spring acting yieldingly to urge the valve memberforwardly into its advanced orifice closing position, a latch leverextending from the coupler plate transversely of said arm of saidbracket above the upper edge thereof, said edge of said arm having asuccession of upwardly opening notches therein adapted individually toreceive the lower edge of said latch lever and releasably hold the valvemember in given position of its longitudinal adjustment, the lip on saidwasher being adapted to be Withdrawn from engagement with the abutmentflange on forward movement of the washer on the valve member against theaction of said spring, thus to release the bracket for downward swingingmovement shifting its abutment flange into position clear of the path oflongitudinal movement of the valve member, said key slot connectionbetween the coupler plate and trigger rod enabling said coupler plate tobe released from said trigger rod, thereby to free the valve member forthe rearward withdrawal thereof from said body.

2. A spray gun, as defined in claim 1, wherein the relationship betweenthe key slot enlargement in the coupler plate, and the arm of theswingable bracket, is such that the latch lever, in its latching throw,engages the arm of the normally positioned bracket, and is therebystopped short of a position assumed by said latch lever when the keyslot enlargement in the coupler plate takes position in axialcoincidence with the axis of the trigger rod for the detachment of saidplate from said rod.

3. In a spray gun for applying plaster and the like, a body having achamber therein and a material-receiving opening leading thereinto, anozzle in the front portion of the body having a discharge orificeleading forwardly from said chamber, a cylindrical valve member mountedin the rear portion of the body in axial alignment with the axis of saidorifice, said valve member being endwise slidable relative to the bodyfor longitudinal ad justment of said member and for withdrawal of thesame from said body, said valve member coacting: with said? nozzle toobstruct said orifice, closing or restricting it,

in varying degree depending upon the longitudinal adjustment accordedsaid valve member, said valve memher having therein an axial passagewayfor the passage of air therethrough, said valve member being adapted tobe connected at its rearward end with a flexible air supply line forfeeding air under pressure to said air passageway, a handle extendingfrom the body, an arm a rearwardly extending retainer lip normally inengagement with said abutment flange at a locality in opposition to theopening of said notch therein, a helical expam sion spring encirclingthe valve member, an abutment on valvemember abutted by the front end ofsaid spring, said spring at its rear end abutting said washer and actingyieldingly to urge the valve member forwardly into its advanced!orifice-closing position, a lever carried by the valve member, saidlever extending outwardly from the valve member transversely of saidarm, said arm having a suc cession of notches therein adaptedindividually to receive the latch lever and releasably hold the valvemember in given position of its longitudinal adjustment, the retainerlip on said washer being adapted to be withdrawn from engagement withthe abutment flange on for- Ward movement of the washer on the valvemember against the action of said spring, thus to release the arm forswinging movement shifting its abutment flange into position clear ofthe valve member, thereby to enable said valve member to be withdrawnfrom said body.

4. In a spray gun for applying plaster and the like, a body having achamber therein and a material-receiving opening leading thereinto, anozzle in the front portion of the body having a discharge orificeleading forwardly from said chamber, a cylindrical valve member mountedin the rear portion of the body in axial alignment with the axis of saidorifice and axially movable for endwise removal from and forlongitudinal adjustment relative to said body, said valve membercoacting at its forward portion with said nozzle to close said orificetherein and to open said orifice in varying degree according to thelongitudinal adjustment of said valve member, said member having thereinan axial passageway for the passage of air therethrough, said valvemember being adapted to be connected at its rearward end with a flexibleair supply line communicating with said air passageway, a handledepending from the body, a trigger mounted on the body, said triggerhaving a finger piece located forwardly of said handle and operable by afinger of the hand grasping said handle, connecting means interposedbetween said trigger and valve member, said means acting to shift thevalve member rearwardly upon rearward movement of the trigger, a swing-Y able bracket having an arm pivoted at its forward end to said body,said arm having an abutment flange at its rear end formed with a notchtherein adapted to receive the rear portion of the valve member, ahelical expansion spring encircling the valve member, an abutment on thevalve member engaged by the forward end of said spring, said abutmentflange of said bracket providing a backing for the rear end of saidspring, said spring normally serving yieldingly to urge the valve memberfor wardly into its advanced orifice'closing position, a latch leverextending outwardly from the valve member transversely of the arm ofsaid bracket over the upper edge thereof, said edge of said arm having asuccession of upwardly opening notches therein adapted individually toreceive the lower edge of said latch lever and releasably hold the Valvemember in given position of its longitudinal adjustment, the bracketbeing swingable on the body 7 into position clear of the'valve member,the connection between the trigger and valve member being detachable tofree the valve member for the rearward withdrawal thereof from saidbody.

5. In a spray gun for applying plaster and the like, a body having achamber therein and a material-receiving opening leading thereinto, anozzle in the front portion of the body having a discharge orificeleading forwardly from said chamber, a cylindrical valve member mountedin the rear portion of the body in axial alignment with the axis of saidorifice and axially movable for longitudinal adjustment relative to saidbody, said valve member coacting at its forward portion with said nozzleto close said orifice therein and to open said orifice in varying degreeaccording to the longitudinal adjustment of said valve member, saidvalve member having therein an axial passageway for the passage of airtherethrough, said valve member being adapted to be connected at itsrearward end with a flexible air supply line leading to said airpassageway, a handle depending from the body, a trigger mounted on thebody and operable by a finger of the hand grasping said handle,connecting means inter- 8 posed between said trigger and valve memberacting to shift the valve member rearwardly upon rearward movement ofthe trigger, anal-m extending rearwardly from the body, said arm havingan abutment at the rear end thereof, a helical expansionspringencircling the valve member, an abutment on the valve member engaged bythe forward end of said spring, said spring at itsrear end abutting saidabutment on said arm and acting yieldingly to urge the valve memberforwardly into its advanced orifice-closing position, a latch leverextending outwardly from the valve member transversely of said arm, saidarm having a succession of notches therein adapted individually to,receive said latch lever and releasably hold the valve-member in a givenposition of its longitudinal adjustment.

References Cited in the file of this patent UNITED STATES PATENTS633,228 Cholodkowsky Sept. 19, 1899 2,134,415 Peerstone Apr. 6, 19152,305,269 Moreland Dec. 15, 1942

